Holdback for lathes



Jan, 13, 1925.

B. L. OLOFSSON HOLDBACK F0R`LATHES Filed April G, 1923 ,5.9 3i ZZ l .71 Ff' l. A Z 7*/ H1',

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do J5 m Hummm 4 c Z. Ff al 20:53 l 30,53 lo ,56 fw/611601' 31 l @d y Qy /f/@ 9 Utoring Patented Jan. 13, 1925.

BROR L. OLOESSQN, F BSTON, MASSACHUSETTS.

HOLIDBACK EGR LATHES.

Application filed April 6, 1923. Serial No. 630,357.

To all whom it may concern: methods have been almost universally ad- Be it known that I, Bnor. L. GLorssoN, a hered to. citizen of the United States, and a resident Vith a view to obviating the objections 55 of Boston.I in the county of Suffolk and noted above, and to produce a holdback for State of Massachusetts, have invented an use in holding back work against the live Improvement in Holdbacks for Lathes, of center in a lathe, and particularly with a which the following description, in connecview to rendering such device simple in tion with the accompanying drawings, is a structure and eiiicient in operation, I have 60 specification, like letters on the drawings designed the subject matter of the present representing like parts. invention which consists essentially of a My present invention relates to holdbacks, simple bracket that may be radially attached and more particularly to a hold-back for to, and detached from a face plate of a use in connection with a dog employed to lathe, and associated .with such bracket I 65 hold work in a lathe, milling machine, or have arranged a clamping device which enthe like. gages with the lathe dog attached to the In lathe work, the ordinary lathe dog is inner end of the work and yieldingly holds secured to one end of a piece of work such work by means of the lathe dog against mounted on the live and dead centers inthe the live center, producing in this manner 70 lathe and has a projecting tail that engages a simple, efficient device.

with a slot or hole in the face plate of the The object of my invention, therefore, lathe and by means of which the work is is an improved holdback for use in lathes rotated on the Acenters to enable the necesand the like. sary operations to be performed on the work, In the accompanying drawings illustratsuch as cutting, grinding, or the like. The ing preferred embodiments of my invention,

ordinary lathe dog is amply suiiicient in it- Fig. 1 is a side elevation, partly in section,

self for carrying out such plain, ordinary showing a plurality of my improved holdoperations. It frequently happens, howback devices secured to the face plate of a ever, that work is to be operated on in a lathe and in position to hold back work 80 lathe with the outer end unsupported from against the live center of such lathe;

the dead center such, for example, where it Fig. 2 is a front elevation of Fig. 1, the

is necessary to perform operations on the work being shown in section; outer end of the piece of work. In such Fig. 3 is a fragmentary detail view of a situations, a steady rest is employed to hold modification of my invention associated 85 the outer end of the work in lieu of holding` with the face plate of a lathe, and

the same on the dead center and considerable Fig. 4 is a front elevation of Fig. 3.

difticulty has been experienced heretofore Referring to the drawings, 10 designates in devising means for holding the work the head-stock of a lathe, to the spindle of against the live center. The ordinary manwhich is secured the usual face plate 11 and 90 ner of holding the work against the live extending outwardly from the front end of center under these conditions is to strap the the spindle is the usual live center 12. rl`he dog to the face plate as, at best, such a face plate 11 is provided with a radial slot method is a makeshift, the strapping ar- 13 in which loosely lits the tail 14 of the usrangement frequently breaks with conseual dog 15, which dog is provided with a 95 quent disastrous effects to the work and in setscrew 16 and whereby the dog is clamped many instances to the lathe itself. In an to the work 17. Ordinarily the work 17 is attempt to avoid the necessity of employing supported at one end by the live center 12 the various strapping arrangements for and by the dead center in the tail stock (not holding back the work onto the live center, shown) of the lathe and rotation of the spin- 10Q complicated and cumbersome arrangements die of the lathe causes a rotation of the face have been devisedwhich cannot profitably plate 11 and a consequent rotation of the be employed, particularly in the small shops, work on the centers. When it is desired to with the result that the old time strapping perform operations on the extreme end of the work 17 that is ordinarily supported on the dead center, it becomes necessary to support the outer end of lsuch work 17 by the usual steady rest 18 and in this event it becomes necessary to hold back the work 17 against the live center 12. To efficiently perform this holding back operation, l provide the face plate 11 with one or moreholes 19 in which loosely lits an internally and externally threaded sleeve 20lprovided on its outer end with a flange 21. An angular bracket having one of its arms 22 provided with a perforation through which passes the `sleeve 2O is secured to the face plate 11 by means of the nut 23 that screws onto the outer threaded portion of the sleeve 20, a washer 24 being placed between the nutv23 and the face plate 11. Into the internal threads ofthe sleeve 20 is screwed a threaded bolt 25Y provided on its outer end with a knnrled head 26 and by means of which the bolt 25 is 'rotated.lV This bolt 25 passes througha'slot 27 formed in a plate 28 and intermediate the ends thereof. One endof the plate 28 provided with a reduced portio'n29thlat fits into4 one or the other of the rectangular perforations 30 formedvin the other `arm 31 V,of the angular bracket. The other end of the plate 28 is forked, as shown at 32, and the tines of the fork may be curved, as shown at 33, to lit the contour of the body of the dog 15 or may be'bent, as shown at 34, and this latter construction enablesthe device to engage the lathe dog latbut a `singlepoint. Surrounding the bolt `25 and lying between the plate 28 and the outerA faceof the flange 21 yis a spring 35 which tends to force the outer end of the plate l28 awa-y from the lathe dog 15 and this construction enables me, when the Vbolt 25 is screwed into the threadsof the sleeve 2O,r to hold the work .17 against the live center l2.

K .Inusing this form ofr my inventiolnthe angular vmember comprised of thevarms 22 and 31vis`str'apped to the face plate 11 in the manner shown and asabove described, th'erediiced end 29 of the plate 28 is inserted Vin the 'apl'niopriate perforation 30, the tines or 34 of the plate 28 being brought into engagement with the lathe dog l5, as shown,Y

andthe bolt rotated by means ofthe kniirled head 26 until the desired degree of 1:) rfe`ssiire is placed on the dog 15 Vand therefore on the work ,17. rdinarily but one of sufch devices is sutlic'ient, though two or even more maybe employed, if vdesirable or necessary, and I have, therefore, shown two of such devices diametrically arranged on the face. plate ii.` l p. y c l y leferifing now to l *`i"gs.,3 andy 4 wherein is shown a, modification of my invention, l have provided an angular bracket comprised of arms 36 vand 37 secured to the face plate 11 by an internally threaded bolt 42 that plate 11.

passes through a perforation in the arm 36 and in the face plate 11, the nut 38 engag ing'with the threads on ,the exterior, of the bolt 42clampin`g the arm13'6; and fvaee plate 11 together, a washer 39 being ordinarily provided between the nut 38 and the face Through the 'threads on the interior of the bolt 42 is screwed a bolt 40 pro- `C'idsd on its inner or left hand end with a knurled head 41 and by mea-ns of which the bolt 40 may be screwed into and out of o( of the angulary bracketmember vis prof (relatively speaking) the bolt 42. `lThe arm vided withV alined slots 43 .into Vwhich fit'.

legs 44 formed on end ofna platte145, the`. extreme ends of the legs '44A being curvedor pointed as were the tines of the fork'ends 32 of the embodiment described with .re'r-Y` spect to Figs. land 2. The body of the member 45 is adapted to be engaged by the end of the bolt 40 and itnwill. be obvious that, with the device constructed andassem.-

bled on the Vface plate 11 as above described,

and with the.y ends of the legs 44, engaging withl the bodyy o f the dogv 15 thearm 37 at the alined slots 43, taken in conjunction with `the legs 44, act as a movable pivot about which the member 45 maybe rotated by the end of the shaft 40 engaging with thebody i of the plate 45 andY thatthis structure en?k ables me to exert pressure to any desire'dm the work degree on the dog 15 to hold back 17 against the live center12'. y l Vvlhile have necessarily shown ,and ole-V scribed the preferredfembodimentsAy of my invention somewhat in detail, Vit is tobe understood thatl may vary the size, shape, and arrangement o'f partscomprising niyinventionwithin wide limits without departing from the spirit of the invention and my invention is of great utility vin ,conv

nection with a'll p machines' vemploying a steady rest and dog toturnmthe work, particularly lathes, grinders', milling machines', and the like. Y

Having thus described my invention, what I cla-iin as new is:

1. ln a device of tlieclas's described, the combination of an angularbracket, means for removably rsecuring said bracket to' vthe face plate of a' lathe', a holldback plate piv-vr otally secured to said bracket on yan azii's lying parallel to said faoe plate, and Ineanfs for forcing the outer end of said holdba'ck 1 means toward the face plate. u

2. In a holdback device for lathes and the 'like` the combination, of an internally threaded sleeve, an angular'bracket provided onv one Vari'nwith a plurality of perforations', means rincluding ,the-` internally threaded .sleeve for securing the .bracketto tlfi),,facieV plate of a lathe', yaV holdback plate piv"ta'lly mounted in either jef the peifftiossatwnl,

toit' thfadd int' thesiv and engaging with the holdback plate, and a spring for normally holding the free end of the holdback )late away from the face plate.

3. n a device of the class described, the combination of an angular bracket, means 1for removably securing said bracket to the tace plate of a machine7 a. holdback plate pivotally and removably mounted on said bracket on an axis lying parallel to said face plate, and means associated with said bracket and said holdback plate for holding 10 Work in operative relation to the face plate of the machine.

In testimony whereof, I have signed my name lto this specification.

BROR L. OLOFSSON. 

